Обший каталог Yamawa 2016 - 2017 - страница 817

15. 15. Bored hole size before tapping ( for thread cutting )

• Recommended Bored Hole Size Table for Taper Pipe Threads (PT) (refer to JIS B 0203) <Remarks during tapping> ・PT internal threads have R design on their crests. The taps should cut threads with their thread root. ・ On thread having non-full threads, if you are going to cut effective thread length ℓ, use the tap of long type.

unit: mm

Thread Standards Minor Diameter Recommended Bored reference

Effective Thread Length

Basic Diameter Pipe End have do not have Basic Diameter

(Minimum) Maximum Size of Straight

Size Face) ℓg

Tolerance

axial non-Full the non-Full ℓ t have do not have Thread Thread

in radial

direction Threads1) Threads1) non-Full the non-Full Type Type

direction

c ℓ t Basic Size Basic Size Basic Size Threads Threads

16

PT 1/ - 28 ±0.071 ± 1.13 6.2 4.4 8.566 8.179 8.291 8.1 8.2 13.0 10.5

8

PT 1/ - 19 ± 0.104 ± 1.67 9.4 6.7 11.445 10.858 11.026 10.7 10.9 21.0 12.5

4

PT 3/ - 19 ± 0.104 ± 1.67 9.7 7.0 14.950 14.344 14.513 14.2 14.4 21.0 14.0

8

PT 1/ - 14 ± 0.142 ± 2.27 12.7 9.1 18.631 17.837 18.062 17.6 17.9 25.0 17.0

2

PT 3/ - 14 ± 0.142 ± 2.27 14.1 10.2 24.117 23.236 23.480 23.0 23.3 25.0 19.0

4

PT 1 - 11 ± 0.181 ± 2.89 16.2 11.6 30.291 29.279 29.566 29.0 29.3 32.0 22.0

• PT 1 1/ - 11 ± 0.181 ± 2.89 18.5 13.4 38.952 37.796 38.115 37.6 37.9 32.0 24.5

4

PT 1 1/ - 11 ± 0.181 ± 2.89 18.5 13.4 44.845 43.689 44.008 43.5 43.8 32.0 25.5

2

PT 2 - 11 ± 0.181 ± 2.89 22.8 16.9 56.656 55.231 55.600 55.0 55.4 35.0 28.0

Note 1) Length toward End of Smaller Diameter from Baisc Diameter Position

When Threads have When Threads do not have non-Full Threads the non-Full Threads ⑥ ⑥ Basic Diameter Position

⑦ ⑧

Remarks 1. Opening of Internal Thread (Face of workpiece) is Basic

Diameter Position.

Remarks 2. Effective Thread Length has 2 types, with non-Full Thread

Type and without non-Full Thread Type. Remarks 3. Concerning bored hole shape, considering load on taps, taper bored hole is recommended.

Remarks 4. When applying taper bored hole, by referring to values

shown in columns ②·⑥~⑧, prepare the taper hole by

using pipe reamer (1/16 taper). By referring to values

shown in columns ⑨ and ⑩, select the drill diameter

before reaming by taking reamer's margin into account.

Remarks 5. When preparing straight bored hole, by referring to

values shown in columns ⑨ and ⑩, select drill diameter.